Movable body apparatus, exposure apparatus, manufacturing method of flat panel display, device manufacturing method, and movable body drive method

ABSTRACT

A substrate stage apparatus provided with: a substrate holder that can be moved in a plane including an X-axis and a Y-axis; a head unit that can be moved synchronously with the substrate holder along the Y-axis; an encoder system for measuring substrate position, the system including a scale disposed on the substrate holder, and heads disposed on the head unit, and acquiring the X-axis direction and the Y-axis direction position information of the substrate holder on the basis of the output of the heads; an encoder system for measuring head-unit position, the system acquiring the Y-axis direction position information of the head unit; and a position control system that controls the position of the substrate holder within the XY plane on the basis of the output of the encoder system for measuring substrate position and the encoder system for measuring head-unit position.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 15/129,426, filed Nov. 14, 2016, pending, the disclosure of which ishereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to movable body apparatus, exposureapparatus, manufacturing methods of flat panel displays, devicemanufacturing methods, and movable body drive methods, and moreparticularly to a movable body apparatus and a movable body drive methodin which a movable body is driven along a predetermined two-dimensionalplane, an exposure apparatus provided with the movable body apparatus, amanufacturing method of flat panel displays using the exposureapparatus, and a device manufacturing method using the exposureapparatus.

BACKGROUND ART

Conventionally, in a lithography process for producing electronicdevices (microdevices) such as liquid crystal display devices andsemiconductor devices (integrated circuits), apparatus are used such asan exposure apparatus of a step-and-scan method (a so-called scanningstepper (also called a scanner)), which transfers a pattern formed on amask on a substrate using an energy beam while a mask (photomask) or areticle (hereinafter referred to collectively as a “mask”) and a glassplate or a wafer (hereinafter referred to collectively as a “substrate”)are synchronously moved along a predetermined scanning direction (scandirection).

As this kind of exposure apparatus, an exposure apparatus is known withan optical interferometer system that acquires position informationwithin a horizontal plane of a substrate subject to exposure, using abar mirror (a long mirror) that a substrate stage apparatus has (forexample, refer to PTL 1).

When position information of the substrate is acquired using the opticalinterferometer system, influence of the so-called air fluctuation cannotbe ignored. Also, although the influence of the above air fluctuationcan be reduced using an encoder system, the increasing size of thesubstrate in recent years makes it difficult to prepare a scale that cancover the entire moving range of the substrate.

CITATION LIST Patent Literature

[PTL 1] U.S. Patent Application Publication No. 2010/0018950

SUMMARY OF THE INVENTION Solution to Problem

The present invention was made under the circumstances described above,and from a first aspect, there is provided a movable body apparatus,comprising: a first movable body movable along a predeterminedtwo-dimensional plane which includes a first direction and a seconddirection orthogonal to each other; a second movable body movablesynchronously with the first movable body along the first direction; afirst measurement system, including a first encoder system that has oneof a scale and a head disposed at the first movable body and the otherof the scale and the head disposed at the second movable body, thatacquires position information of the first movable body at least in thesecond direction on the basis of output of the head; a secondmeasurement system that acquires position information of the secondmovable body in the first direction; and a position control system thatperforms position control of the first movable body within thetwo-dimensional plane, on the basis of output of the first measurementsystem and the second measurement system.

In the description, “move synchronously with” means that the first andsecond mobile bodies move in a state roughly maintaining a relativeposition relation, and that it is not limited to a case in which thefirst and second movable bodies move in a state where their positions(moving direction and velocity) match exactly.

According to this apparatus, position information of the first movablebody in the second direction is acquired by the first encoder system.Since the second movable body moves in the first direction synchronouslywith the first movable body, the first encoder system can acquire theposition information of the first movable body in the second direction,regardless of the position of the first movable body in the firstdirection. Also, the position information of the first movable body inthe first direction can be acquired, on the basis of the output of thesecond measurement system. As described, the first encoder system onlyhas to cover the movement range of the first movable body in the seconddirection, which is efficient.

From a second aspect of the present invention, there is provided anexposure apparatus, comprising: the movable body apparatus according tothe first aspect of the present invention in which a predeterminedobject is held by the first movable body; and a pattern formationapparatus, while driving a pattern holding body which holds apredetermined pattern in the second direction synchronously with thefirst movable body, forms the pattern on the object via the patternholding body using an energy beam.

From a third aspect of the present invention, there is provided amanufacturing method of a flat panel display, comprising: exposing theobject using the exposure apparatus according to the second aspect ofthe present invention; and developing the object which has been exposed.

From a fourth aspect of the present invention, there is provided adevice manufacturing method, comprising: exposing the object using theexposure apparatus according to the second aspect of the presentinvention; and developing the object which has been exposed.

From a fifth aspect of the present invention, there is provided amovable body drive method in which a movable body is driven along apredetermined two-dimensional plane that includes a first direction anda second direction orthogonal to each other, comprising: driving a firstmovable body in the second direction, on the basis of an output of anencoder system that has a head disposed at one of the first movable bodyand a second movable body placed facing the first movable body, and ascale disposed at the other of the first movable body and the secondmovable body; driving the first movable body in the first direction;driving the second movable body in the first direction synchronouslywith the first movable body when the first movable body moves in thefirst direction; and performing position control of the first movablebody in the two-dimensional plane, on the basis of position informationof the first movable body in the second direction acquired from theoutput of the encoder system and position information of the secondmovable body in the first direction.

From a sixth aspect of the present invention, there is provided amovable body apparatus, comprising: a first movable body movable in afirst direction; a second movable body movable in a second directionintersecting the first direction, disposed facing the first movablebody; a driving system that drives the second movable body in the seconddirection, corresponding to movement of the first movable body in thesecond direction; a first measurement system, including a first encodersystem that has one of a head which emits a measurement beam and a scalewhere the measurement beam is irradiated disposed at the first movablebody and the other of the head and the scale disposed at the secondmovable body, that acquires relative position information between thefirst movable body and the second movable body, on the basis of outputof the head receiving the measurement beam via the scale; a secondmeasurement system that acquires position information of the secondmovable body, different from the relative position information; and aposition control system that performs position control of the firstmovable body, on the basis of output of the first measurement system andthe second measurement system.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A view schematically showing a structure of a liquid crystalexposure apparatus according to a first embodiment.

FIG. 2 A view showing an example of a substrate stage apparatus that theliquid crystal exposure apparatus in FIG. 1 is equipped with.

FIG. 3A is a view schematically showing a structure of a mask encodersystem, and FIG. 3B is an enlarged view of a part of the mask encodersystem (section A in FIG. 3A).

FIG. 4A is a view schematically showing a structure of a substrateencoder system, and FIGS. 4B and 4C are enlarged views of a part of thesubstrate encoder system (section B in FIG. 4A).

FIG. 5 Aside view of a head unit that the substrate encoder system has.

FIG. 6 A sectional view of line C-C in FIG. 5.

FIG. 7 A conceptual diagram of the substrate encoder system.

FIG. 8 A block diagram showing an input/output relation of a maincontroller that mainly structures a control system of the liquid crystalexposure apparatus.

FIG. 9A is a view (No. 1) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 9B is a view (No. 2)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 10A is a view (No. 2) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 10B is a view (No. 2)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 11A is a view (No. 3) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 11B is a view (No. 3)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 12A is a view (No. 4) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 12B is a view (No. 4)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 13A is a view (No. 5) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 13B is a view (No. 5)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 14A is a view (No. 6) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 14B is a view (No. 6)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 15A is a view (No. 7) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 15B is a view (No. 7)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 16A is a view (No. 8) showing an operation of the mask encodersystem at the time of exposure operation, and FIG. 16B is a view (No. 8)showing an operation of the substrate encoder system at the time ofexposure operation.

FIG. 17 A partially enlarged view of a mask encoder system according toa second embodiment.

FIG. 18 A partially enlarged view of a substrate encoder systemaccording to a third embodiment.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment will be described, with reference toFIGS. 1 to 16B.

FIG. 1 schematically shows a structure of a liquid crystal exposureapparatus 10 according to a first embodiment. Liquid crystal exposureapparatus 10 is a projection exposure apparatus of a step-and-scanmethod, or a so-called scanner. The exposure target of liquid crystalexposure apparatus 10 is a glass substrate P (hereinafter simplyreferred to as a substrate P) having a rectangular-shape (square-shape),used in, for example, a liquid crystal display device (a flat paneldisplay).

Liquid crystal exposure apparatus 10 includes an illumination system 12,a mask stage apparatus 14 that holds a mask M on which a circuit patternand the like are formed, a projection optical system 16, an apparatusmain section 18, a substrate stage apparatus 20 that holds substrate Phaving a resist (sensitive agent) coated on its surface (the surfacefacing the +Z side in FIG. 1), and a control system for these parts. Inthe description below, a direction in which mask M and substrate P arerelatively scanned with respect to projection optical system 16 at thetime of exposure will be described as an X-axis direction, a directionorthogonal to the X-axis within a horizontal plane will be described asa Y-axis direction, and a direction orthogonal to the X-axis and theY-axis will be described as a Z-axis direction. Rotation directionsaround the X-axis, the Y-axis, and the Z-axis will be θx, θy, and θzdirections, respectively. Also, positions in regard to the X-axis, theY-axis, and the Z-axis directions will be described as X position, Yposition, and Z position, respectively.

Illumination system 12 is structured similarly to the illuminationsystem disclosed in, for example, U.S. Pat. No. 5,729,331. Illuminationsystem 12 irradiates light emitted from a light source not illustrated(for example, a mercury lamp) on mask M as an illumination light forexposure (illumination light) IL, via parts including a reflectionmirror, a dichroic mirror, a shutter, a wavelength selection filter andvarious kinds of lenses, none of which are illustrated. As illuminationlight IL, lights such as, for example, i-line (wavelength 365 nm),g-line (wavelength 436 nm), and h-line (wavelength 405 nm) (or asynthetic light of the above i-line, g-line, and h-line) are used.

Mask stage apparatus 14 includes a mask holder 40 that holds mask M by,for example, vacuum chucking, a mask driving system 91 (not illustratedin FIG. 1, refer to FIG. 8) that drives mask holder 40 in a scanningdirection (the X-axis direction) in predetermined long strokes as wellas finely drive mask holder 40 appropriately in the Y-axis direction andthe θz direction, and a mask position measurement system for acquiringposition information (including rotation quantity information in the θzdirection. The same shall apply hereinafter) of mask holder 40 in an XYplane. Mask holder 40 consists of a frame-shaped member that has anopening section of a rectangular-shape in a planar view formed, as isdisclosed in, for example, U.S. Patent Application Publication No.2008/0030702. Mask holder 40 is mounted on a pair of mask guides 42,via, for example, an air bearing (not shown). The pair of mask guides 42is fixed to an upper mount section 18 a, which is a part of apparatusmain section 18. Mask driving system 91, for example, includes a linearmotor (not shown).

Mask position measurement system is equipped with a mask encoder system48. Mask encoder system 48 includes a pair of encoder head units 44(hereinafter simply referred to as head units 44) fixed to upper mountsection 18 a via an encoder base 43, and a plurality of encoder scales46 (overlapping in the depth direction of the page surface of FIG. 1,refer to FIG. 3A) placed corresponding to the above pair of head units44 on the lower surface of mask holder 40. The structure of mask encodersystem 48 will be described in detail later in the description.

Projection optical system 16 is placed below mask stage apparatus 14.Projection optical system 16 is a so-called multi-lens projectionoptical system whose structure is similar to the projection opticalsystem disclosed in, for example, U.S. Pat. No. 6,552,775, and isequipped with a plurality of optical systems (e.g., 11 in theembodiment, refer to FIG. 3A) that form upright images with, forexample, a double telecentric non-magnification system.

In liquid crystal exposure apparatus 10, when an illumination area onmask M is illuminated by illumination light IL from illumination system12, the illumination light that has passed mask M forms a projectionimage (a part of an erected image) of the circuit pattern of mask Mwithin the illumination area via projection optical system 16, onsubstrate P in an irradiation area (exposure area) of the illuminationlight conjugate to the illumination area. Then, scanning exposure isperformed of a shot area on substrate P, by mask M relatively moving inthe scanning direction with respect to the illumination area(illumination light IL) as well as substrate P relatively moving in thescanning direction with respect to the exposure area (illumination lightIL), and the pattern formed on mask M is transferred on the shot area.

Apparatus main section 18, which supports the above mask stage apparatus14 and projection optical system 16, is installed on a floor 11 of aclean room via a plurality of anti-vibration devices 19. Apparatus mainsection 18, which is structured similarly to the apparatus main sectiondisclosed in, for example, U.S. Patent Application Publication No.2008/0030702, has upper mount section 18 a (also referred to as anoptical surface plate) for supporting projection optical system 16, apair of lower mount sections 18 b (one of the pair is not shown in FIG.1 because of being arranged overlapping in the depth direction of thepage surface, refer to FIG. 2), and a pair of middle mound sections 18c.

Substrate stage apparatus 20, which is for positioning substrate P withhigh precision with respect to projection optical system 16 (exposurelight IL), drives substrate P along a horizontal plane (the X-axisdirection and the Y-axis direction) with predetermined long strokes, aswell as drive substrate P finely in directions of six degrees offreedom. Although the structure of substrate stage apparatus 20 is notrestricted in particular, it is preferable to use a stage apparatus of aso-called coarse/fine movement structure that includes a gantry typetwo-dimensional coarse movement stage and a fine movement stage which isdriven finely with respect to the two-dimensional coarse movement stage,as is disclosed in, for example, U.S. Patent Application Publication No.2008/129762, or in U.S. Patent Application Publication No. 2012/0057140.

FIG. 2 shows an example of substrate stage apparatus 20 of the so-calledcoarse/fine movement structure used in liquid crystal exposure apparatus10 of the present embodiment. Substrate stage apparatus 20 is equippedwith a pair of base frames 22, a Y coarse movement stage 24, an X coarsemovement stage 26, a weight-canceling device 28, a Y step guide 30, anda fine movement stage 32.

Base frame 22, which consists of a member extending in the Y-axisdirection, is installed on floor 11 in a state vibrationally isolatedfrom apparatus main section 18. An auxiliary base frame 23 is alsoplaced, in between the pair of lower mount sections 18 b of apparatusmain section 18. Y coarse movement stage 24 has a pair of X beams 25(one of the pair is not shown in FIG. 2) laid extending over the pair ofbase frames 22. Auxiliary base frame 23 previously described supportsthe center in the longitudinal direction of X beam 25 from below. Ycoarse movement stage 24 is driven with predetermined long strokes inthe Y-axis direction on the pair of base frames 22 via a plurality of Ylinear motors, which are a part of a substrate driving system 93 (notshown in FIG. 2, refer to FIG. 8) for driving substrate P in directionsof six degrees of freedom. X coarse movement stage 26 is mounted on Ycoarse movement stage 24 in a state built over the pair of X beams 25. Xcoarse movement stage 26 is driven with predetermined long strokes inthe X-axis direction on Y coarse movement stage 24 via a plurality of Xlinear motors, which are a part of substrate driving system 93. Since Xcoarse movement stage 26 has its relative movement mechanicallyrestricted in the Y-axis direction with respect to the Y coarse movementstage 24, it is moved in the Y-axis direction integrally with Y coarsemovement stage 24.

Weight-canceling device 28 is inserted between the pair of X beams 25,and is also mechanically joined to X coarse movement stage 26. Thisallows weight-canceling device 28 to move in predetermined long strokesin the X-axis and/or Y-axis direction(s) integrally with X coarsemovement stage 26. Y step guide 30, which consists of a member extendingin the X-axis direction, is mechanically joined to Y coarse movementstage 24. This allows Y step guide 30 to move in predetermined longstrokes in the Y-axis direction integrally with Y coarse movement stage24. The above weight-canceling device 28 is mounted on Y step guide 30via a plurality of air bearings. Weight-canceling device 28, when Xcoarse movement stage 26 moves only in the X-axis direction, moves inthe X-axis direction on Y step guide 30 which is in a stationary state,and when X coarse movement stage 26 moves in the Y-axis direction(including the case when there is movement also in the X-axisdirection), moves in the Y-axis direction integrally with Y step guide30 (so as not to fall from Y step guide 30).

Fine movement stage 32, which consists of a plate shaped (or a boxlike)member having a rectangular shape in a planar view, is supported frombelow in the center by weight-canceling device 28 via a sphericalbearing device 29, in a state freely swingable with respect to the XYplane. A substrate holder 34 is fixed to the upper surface of finemovement stage 32, and substrate P is mounted on substrate holder 34.Fine movement stage 32, which includes a stator that X coarse movementstage 26 has and a mover that fine movement stage 32 has, is finelydriven by a plurality of linear motors 33 (e.g., voice coil motors) thatstructure a part of substrate driving system 93 (not shown in FIG. 2,refer to FIG. 8) described above in directions of six degrees of freedomwith respect to X coarse movement stage 26. Fine movement stage 32 alsomoves in predetermined long strokes in the X-axis and/or Y-axisdirection(s) along with X coarse movement stage 26, according to thrustgiven by X coarse movement stage 26 via the above plurality of linearmotors 33. Details of the structure of substrate stage apparatus 20described so far (excluding the measurement system) are disclosed in,for example, U.S. Patent Application Publication No. 2012/0057140.

Further, substrate stage apparatus 20 has a substrate Positionmeasurement system for acquiring position information of fine movementstage 32 (namely, substrate holder 34 and substrate P) in directions ofsix degrees of freedom. The substrate Position measurement systemincludes a Z tilt position measurement system 98 for acquiring positioninformation of substrate P in the Z-axis, the θx, and θy directions(hereinafter referred to as a Z tilt direction), and a substrate encodersystem 50 for acquiring position information of substrate P in the XYplane, as is shown in FIG. 8. Z tilt position measurement system 98 isequipped with a plurality of Z sensors 36 that includes a probe 36 aattached to the lower surface of fine movement stage 32 and a target 36b attached to weight-canceling device 28, as is shown in FIG. 2. Theplurality of Z sensors 36, e.g., four (at least three), are placed at apredetermined spacing, around an axis parallel to the Z-axis whichpasses through the center of fine movement stage 32. A main controller90 (refer to FIG. 8) acquires Z position information, and rotationquantity information in the θx and θy directions of fine movement stage32, on the basis of the output of the above plurality of Z sensors 36.

The structure of Z tilt position measurement system 98 including theabove Z sensors 36 is disclosed in detail in, for example, U.S. PatentApplication Publication No. 2010/0018950. The structure of substrateencoder system 50 will be described later in the description.

Next, the structure of mask encoder system 48 will be described, usingFIGS. 3A and 3B. As is typically shown in FIG. 3A, a plurality ofencoder scales 46 (hereinafter simply referred to as scales 46) areplaced in areas on the +Y side and the −Y side of mask M (morespecifically, an opening section not shown for housing mask M) in maskholder 40. Although FIG. 3A illustrates the plurality of scales 46 in asolid line placed on the upper surface of mask holder 40 to facilitateunderstanding, the plurality of scales 46 are actually placed at thelower surface side of mask holder 40 so that the Z position of the lowersurface of each of the plurality of scales 46 coincides with the Zposition of the lower surface (pattern surface) of mask M, asillustrated in FIG. 1.

In mask holder 40 of the present embodiment, scales 46 are placed in theX-axis direction at a predetermined spacing, e.g., three each, in theareas on the +Y side and −Y side of mask M. That is, mask holder 40 hasa total of, e.g., siX scales 46. The plurality of scales 46 are eachsubstantially the same at the +Y side and −Y side of mask M, except forthe point that the scales are placed symmetrically in the verticaldirection of the page surface. Scales 46 consist of plate-like(strip-shaped) members with a rectangular-shape in a planar viewextending in the X-axis direction, made of, for example, quartz glass.Mask holder 40 is made of, for example, ceramics, and the plurality ofscales 46 are fixed to mask holder 40.

As is shown in FIG. 3B, X scales 47 x are formed in areas on one side(the −Y side in FIG. 3B) in the width direction at the lower surface(the surface facing the −Z side in the present embodiment) of scales 46.Also, Y scales 47 y are formed in areas on the other side (the +Y sidein FIG. 3B) in the width direction on the lower surface of scales 46. Xscales 47 x, which are formed at a predetermined pitch in the X-axisdirection (the X-axis direction being the periodic direction), arestructured by reflection type diffraction gratings (X gratings) whichhave a plurality of grid lines extending in the Y-axis direction.Similarly, Y scales 47 y, which are formed at a predetermined pitch inthe Y-axis direction (the Y-axis direction being the periodicdirection), are structured by reflection type diffraction gratings (Ygratings) which have a plurality of grid lines extending in the X-axisdirection. In X scales 47 x and Y scales 47 y of the present embodiment,the plurality of grid lines are formed, for example, at a spacing of 10nm or less. The spacing (pitch) between the grids shown in FIGS. 3A and3B are illustrated remarkably wider than the actual spacing, forconvenience of illustration. The same can be said for other drawings.

Further, as shown in FIG. 1, a pair of encoder bases 43 is fixed to theupper surface of upper mount section 18 a. The pair of encoder bases 43is placed, so that one of the pair is at the −X side of mask guide 42 atthe +X side, and the other is at the +X side of mask guide 42 at the −Xside (that is, placed in the area between the pair of mask guides 42). Apart of the above projection optical system 16 is also placed betweenthe pair of encoder bases. Encoder base 43 consists of a memberextending in the X-axis direction, as shown in FIG. 3A. The pair ofencoder bases 43 each has an encoder head unit 44 (hereinafter simplyreferred to as a head unit 44) fixed to the center portion in thelongitudinal direction. That is, head unit 44 is fixed to apparatus mainsection 18 (refer to FIG. 1) via encoder base 43. Since the pair of headunits 44 are substantially the same at the +Y side and −Y side of maskM, except for the point that the units are placed symmetrically in thevertical direction of the page surface, only one of the pair of headunits (the −Y side unit) will be described below.

Head unit 44, as shown in FIG. 3B, has a unit base 45 which consists ofa plate-like member with a rectangular-shape in a planar view. A pair ofX heads 49 x placed apart in the X-axis direction and a pair of Y heads49 y placed apart in the X-axis direction are fixed to unit base 45.That is, mask encoder system 48 has, e.g., four X heads 49 x, alongwith, e.g., four Y heads 49 y. Although FIG. 3B illustrates one of the Xheads 49 x and one of the Y heads 49 placed within a single housing andthe other X head 49 x and the other Y head 49 y placed within anotherhousing, the pair of X heads 49 x and the pair of Y heads 49 y may eachbe placed independently. Also, although FIG. 3B illustrates the pair ofX heads 49 x and the pair of Y heads 49 y placed above (the +Z side)scale 46 to facilitate understanding, the pair of X heads 49 x areactually placed below X scale 47 y, and the pair of Y heads 49 y areactually placed below Y scale 47 y (refer to FIG. 1).

The pair of X heads 49 x and the pair of Y heads 49 y are fixed to unitbase 45, so that the distance between the pair of X heads 49 x and thedistance between the pair of Y heads 49 y do not change, for example,due to vibration or the like. Also, unit base 45 itself is formed usinga material whose thermal expansion is lower than scale 46 (or equal toscale 46) so that the distance between the pair of X heads 49 x and thedistance between the pair of Y heads 49 y do not change, for example,due to temperature change or the like.

X heads 49 x and Y heads 49 y, which are encoder heads of the so-calleddiffraction interference method as is disclosed in, for example, U.S.Patent Application Publication No. 2008/0094592, irradiate measurementbeams on the corresponding scales (X scales 47 x and Y scales 47 y) andby receiving the beams from the scales, supply information ondisplacement quantity of mask holder 40 (namely mask M, refer to FIG.3A) to main controller 90 (refer to FIG. 8). That is, in mask encodersystem 48, for example, four X heads 49 x and X scales 47 x (differentdepending on the X position of mask holder 40) facing X heads 49 xstructure, for example, four X linear encoders 92 x (not shown in FIG.3B, refer to FIG. 8) for acquiring position information of mask M in theX-axis direction, and for example, four Y heads 49 y and Y scales 47 y(different depending on the X position of mask holder 40) facing Y heads49 y structure, for example, four Y linear encoders 92 y (not shown inFIG. 3B, refer to FIG. 8) for acquiring position information of mask Min the Y-axis direction.

Main controller 90 acquires position information of mask holder 40 inthe X-axis direction and the Y-axis direction, on the basis of theoutput of, for example, the four X linear encoders 92 x, and forexample, the four Y linear encoders 92 y, at a resolution of, forexample, 10 nm or less, as shown in FIG. 8. Main controller 90 alsoacquires 19Z position information (rotation quantity information) ofmask holder 40, on the basis of at least two outputs of, e.g., the fourX linear encoders 92 x (or, for example, four Y linear encoders 92 y).Main controller 90 controls the position of mask holder 40 in the XYplane, using mask driving system 91, on the basis of positioninformation of mask holder 40 within the XY plane acquired frommeasurement values of the above mask encoder system 48.

Now, as shown in FIG. 3A, mask holder 40 has, for example, three scales46, placed in the X-axis direction at a predetermined spacing in each ofthe areas at the +Y side and the −Y side of mask M, as is describedabove. In addition, mask holder 40 is driven in the X-axis direction,between a position where head unit 44 (all of the pair of X heads 49 xand the pair of Y heads 49 y (each refer to FIG. 3B)) faces scale 46located outermost to the +X side of, for example, the three scales 46placed in the X-axis direction at a predetermined spacing, and aposition where head unit 44 faces scale 46 located outermost to the −Xside.

And, in mask stage apparatus 14 of the present embodiment, the spacingbetween each head of the pair of X heads 49 x and each head of the pairof Y heads 49 y that one head unit 44 has is set wider than the spacingbetween the adjacent scales 46, as shown in FIG. 3B. This allows atleast one head of the pair of X heads 49 x to constantly face X scale 47x and at least one head of the pair of Y heads 49 y to constantly face Yscale 47 y, in mask encoder system 48. Mask encoder system 48,therefore, is able to supply position information of mask holder 40(refer to FIG. 3A) to main controller 90 (refer to FIG. 8) withoutinterruption.

Specifically, for example, when mask holder 40 (refer to FIG. 3A) movesto the +X side, mask encoder system 48 moves through the following statein the order below; a first state in which the pair of heads 49 x bothface X scale 47 x at the +X side of the pair of X scales 47 x which areadjacent (the state shown in FIG. 3B), a second state in which X head 49x at the −X side faces an area between the above pair of X scales 47 xwhich are adjacent (facing neither of the X scales 47 x) and X head 49 xat the +X side faces the above X scale 47 x at the +X side, a thirdstate in which X head 49 x at the −X side faces the above X scale 47 xat the −X side and X head 49 x at the +X side also faces X scale 47 x atthe +X side, a fourth state in which X head 49 x at the −X side facesscale 47 x at the −X side and X head 49 x at the +X side faces an areabetween the pair of X scales 47 x (facing neither of the X scales 47 x),and a fifth state in which the pair of heads 49 x both face X scale 47 xat the −X side. Therefore, at least one of the X heads 49 x constantlyfaces X scale 47 x.

Main controller 90 (refer to FIG. 8) acquires position information ofmask holder 40 on the basis of the average value of the output of thepair of X heads 49 in the above first, third and fifth states. Maincontroller 90 also acquires X position information of mask holder 40 onthe basis of only the output of X head 49 x at the +X side in the abovesecond state, and acquires X position information of mask holder 40 onthe basis of only the output of X head 49 x at the −X side in the abovefourth state. Therefore, the measurement values of mask encoder system48 are successively acquired without interruption.

Next, a structure of substrate encoder system 50 will be described.Substrate encoder system 50, as shown in FIG. 1, is equipped with aplurality of encoder scales 52 placed at substrate stage apparatus 20(overlapping in the depth direction of the page surface of FIG. 1, referto FIG. 4A), an encoder base 54 fixed to the lower surface of uppermount section 18 a, a plurality of encoder scales 56 fixed to the lowersurface of encoder base 54, and a pair of encoder head units 60.

In substrate stage apparatus 20 of the present embodiment in areas atthe +Y side and the −Y side of substrate P, for example, five encoderscales 52 (hereinafter simply referred to as scales 52) are placed inthe X-axis direction at a predetermined spacing, as is typically shownin FIG. 4A. That is, substrate stage apparatus 20 has a total of, forexample, 10 scales 52. The plurality of scales 52 are each substantiallythe same, except for the point that the scales at the +Y side and −Yside of substrate P are placed symmetrically in the vertical directionof the page surface. Scales 52 consist of plate-like (strip-shaped)members with a rectangular-shape in a planar view extending in theX-axis direction, made of, for example, quartz glass, similarly toscales 46 (refer to FIG. 3A for each scale) of the above mask encodersystem 48.

Note that, although the plurality of scales 52 are illustrated so thatthe scales appear to be fixed to the upper surface of substrate holder34 to facilitate understanding in FIGS. 1 and 4A, the plurality ofscales 52 are actually fixed to fine movement stage 32 via scale bases51 in a state separate from substrate holder 34, as shown in FIG. 2(note that FIG. 2 illustrates the case when the plurality of scales 52are placed at the +X side and −X side of substrate P). In some cases,however, the plurality of scales 52 may actually be fixed on substrateholder 34. The description below will be made assuming that theplurality of scales 52 are placed on substrate holder 34.

As shown in FIG. 4B, X scales 53 x are formed in areas on one side (the−Y side in FIG. 4B) in the width direction on the upper surface ofscales 52. Also, Y scales 53 y are formed in areas on the other side(the +Y side in FIG. 4B) in the width direction on the upper surface ofscales 52. Since the structure of X scales 53 x and Y scales 53 y is thesame as X scales 47 x and Y scales 47 y (refer to FIG. 3B for eachscale) formed on scales 46 of the above mask encoder system 48 (refer toFIG. 3A for each part), the description thereabout will be omitted.

Encoder base 54, as it can be seen from FIGS. 5 and 6, is equipped witha first section 54 a, which consists of a plate-like member extending inthe Y-axis direction fixed to the lower surface of upper mount section18 a, and a second section 54 b, which consists of a member having aU-shaped XZ section extending in the Y-axis direction fixed to the lowersurface of the first section 54 a. Encoder base 54, as a whole, isformed in a cylindrical shape extending in the Y-axis direction.Although the X position of encoder base 54 roughly coincides with the Xposition of the center of projection optical system 16 as shown in FIG.4A, encoder base 54 is placed free from contact with projection opticalsystem 16. Encoder base 54 and projection optical system 16 may also beseparately placed; at the +Y side and the −Y side. To the lower surfaceof encoder base 54, a pair of Y linear guides 63 a is fixed, as shown inFIG. 6. The pair of Y linear guides 63 a each consists of a memberextending in the Y-axis direction, and are placed parallel to each otherat a predetermined spacing in the X-axis direction.

To the lower surface of encoder base 54, a plurality of encoder scales56 (hereinafter simply referred to as scales 56) are fixed. Scales 56 inthe present embodiment are placed as shown in FIG. 1, with, for example,two scales in the area at the +Y side of projection optical system 16,and for example, two scales in the area at the −Y side of projectionoptical system 16, with the scales set apart in the Y-axis direction.That is, a total of, for example, four scales 56 are fixed to encoderbase 54. Each of the plurality of scales 56 is substantially the same.Scales 56, which consist of plate-like (strip-shaped) members with arectangular-shape in a planar view extending in the Y-axis direction,are made of, for example, quartz glass, similarly to scales 52 placed onsubstrate stage apparatus 20. Although FIG. 4A illustrates the pluralityof scales 56 in a solid line placed on the upper surface of encoder base54 to facilitate understanding, the plurality of scales 56 are actuallyplaced at the lower surface side of encoder base 54, as illustrated inFIG. 1.

As shown in FIG. 4C, X scales 57 x are formed in areas on one side (the+X side in FIG. 4C) in the width direction on the lower surface ofscales 56. Also, Y scales 57 y are formed in areas on the other side(the −X side in FIG. 4C) in the width direction on the lower surface ofscales 56. Since the structure of X scales 57 x and Y scales 57 y is thesame as X scales 47 x and Y scales 47 y (refer to FIG. 3B for eachscale) formed on scales 46 of the above mask encoder system 48 (refer toFIG. 3A for each part), the description thereabout will be omitted.

Referring back to FIG. 1, the pair of encoder head units 60 (hereinaftersimply referred to as head units 60) is placed apart in the Y-axisdirection below encoder base 54. Since each of the pair of head units 60is substantially the same except for the point that the head units areplaced symmetrically in the lateral direction of the page surface inFIG. 1, hereinafter only one of the head units (at the −Y side) will bedescribed. Head unit 60, as shown in FIG. 5, is equipped with a Y slidetable 62, a pair of X heads 64 x, a pair of Y heads 64 y (not shown inFIG. 5 because of being hidden behind the pair of X heads 64 x in thedepth of the page surface, refer to FIG. 4C), a pair of X heads 66 x(one of the X heads 66 x is not shown in FIG. 5, refer to FIG. 4B), apair of Y heads 66 y (one of the Y heads 66 y is not shown in FIG. 5,refer to FIG. 4B), and a belt driving device 68 for driving Y slidetable 62 in the Y-axis direction.

Y slide table 62, which consists of a plate-like member having arectangular-shape in a planar view, is placed below encoder base 54 viaa predetermined clearance with respect to encoder base 54. Y slide table62 is also set, so that the Z position is to the +Z side than that ofsubstrate holder 34 which substrate stage apparatus 20 has (each referto FIG. 1), regardless of the Z tilt position of substrate holder 34.

To the upper surface of Y slide table 62, as shown in FIG. 6, aplurality of Y slide members 63 b (e.g., two (refer to FIG. 5) withrespect to one Y linear guide 63 a) is fixed that engages with the aboveY linear guide 63 a in a freely slidable manner in the Y-axis directionvia a rolling body not shown (for example, a plurality of balls of acirculation type). Y linear guide 63 a and Y slide members 63 bcorresponding to Y linear guide 63 a structure a mechanical Y linearguide device 63, as is disclosed in, for example, U.S. Pat. No.6,761,482, and Y slide table 62 is guided straightforward in the Y-axisdirection with respect to encoder base 54, via the pair of Y linearguide devices.

Belt driving device 68, as shown in FIG. 5, is equipped with a rotationdriving device 68 a, a pulley 68 b, and a belt 68 c. Note that beltdriving device 68 can be placed independently for driving slide table 62at the −Y side and for driving slide table 62 at the +Y side (not shownin FIG. 5, refer to FIG. 4A), or the pair of Y slide tables 62 may bedriven integrally by a single belt driving device 68.

Rotation driving device 68 a, which is fixed to encoder base 54, isequipped with a rotation motor (not shown). Main controller 90 (refer toFIG. 8) controls the number of rotations and the rotation direction ofthe rotation motor. Rotation driving device 68 a rotationally drivespulley 68 b around an axis parallel to the X-axis. Belt driving device68, although it is not illustrated, has another pulley, which is placedapart in the Y-axis direction from the above pulley 68 b and is attachedto encoder base 54 in a state freely rotatable around the axis parallelto the X-axis. Belt 68 c has one end and the other end connected to Yslide table 62, in addition to having two places at the mid portion inthe longitudinal direction of the belt wound around the above pulley 68b and the another pulley (not shown), in a state where a predeterminedtension is given to the pulleys. A part of belt 68 c is inserted intoencoder base 54, for example, so as to suppress adhesion of dust frombelt 68 c on scales 52 and 56. By pulley 68 being rotationally driven, Yslide table 62 is pulled by belt 68 c and moves back and forth withpredetermined strokes in the Y-axis direction.

Main controller 90 (refer to FIG. 8) synchronously drives, asappropriate, one of the head units 60 (the +Y side) placed further tothe +Y side than projection optical system 16, for example, below twoscales 56, and the other of the head units 60 (the −Y side) placedfurther to the −Y side than projection optical system 16, for example,below two scales 56, with predetermined strokes in the Y-axis direction.Note that although belt driving device 68 including toothed pulley 68 band toothed belt 68 c is used as an actuator for driving Y slide table62, the present embodiment is not limited to this, and a friction wheeldevice including a pulley without teeth and a belt may also be used. Inaddition, the flexible member that pulls Y slide table 62 is not limitedto a belt, and may also be members such as, for example, a rope, a wire,or a chain. In addition, the kind of actuator for driving Y slide table62 is not limited to belt driving device 68, and may be other drivingdevices such as, for example, a linear motor or a feed screw device.

X head 64 x, Y head 64 y (not shown in FIG. 5, refer to FIG. 6) X head66 x and Y head 66 y, which are each an encoder head of the so-calleddiffraction interference method similar to X head 49 x and Y head 49 ythat the above mask encoder system 48 has, are fixed to Y slide table62. Now, in head unit 60, the pair of Y heads 64 y, the pair of X heads64 x, the pair of Y heads 66 y and the pair of X heads 66 x are fixed toY slide table 62, so that the distance between the heads of each pairdoes not change due to, for example, vibration or the like. Y slidetable 62 itself also is formed of a material having a thermal expansioncoefficient lower than scales 52 and 56 (or equal to scales 52 and 56),so that the distance does not change between the heads of each pair; thepair of Y heads 64 y, the pair of X heads 64 x, the pair of Y heads 66 yand the pair of X heads 66 x, due to, for example, temperature change orthe like.

As shown in FIG. 7, two places (two points) separate from each other inthe Y-axis direction on X scale 57 x are irradiated with measurementbeams from the pair of X heads 64 x, and two places (two points)separate from each other in the Y-axis direction on Y scale 57 y areirradiated with measurement beams from the pair of Y heads 64 y.Substrate encoder system 50 supplies information on displacementquantity of Y slide table 62 (not shown in FIG. 7, refer to FIGS. 5 and6) to main controller 90 (refer to FIG. 8) by receiving beams fromscales corresponding to the above X heads 64 x and Y heads 64 y. Thatis, in substrate encoder system 50, for example, four X heads 64 x and Xscales 57 x (different according to the Y position of Y slide table 62)facing the X heads 64 x structure, for example, four linear encoders 96x (not shown in FIG. 7, refer to FIG. 8) used for acquiring positioninformation in the Y-axis direction of each of the pair of Y slidetables 62 (that is, the pair of head units 60 (refer to FIG. 1)). And,in substrate encoder system 50, for example, four Y heads 64 y and Yscales 57 y (different according to the Y position of Y slide table 62)facing the Y heads 64 y structure, for example, four Y linear encoders96 y (not shown in FIG. 7, refer to FIG. 8) used for acquiring positioninformation in the Y-axis direction of each of the pair of Y slidetables 62.

Main controller 90 acquires position information of each of the pair ofhead units 60 (refer to FIG. 1) in the X-axis direction and the Y-axisdirection at a resolution of, for example, 10 nm or less, on the basisof the output of, e.g., the four X linear encoders 96 x, and e.g., thefour Y linear encoders 96 y, as shown in FIG. 8. Main controller 90 alsoacquires 19Z position information (rotation quantity information) of oneof the head units 60, on the basis of the output of, e.g., two X linearencoders 96 x (or, e.g., two Y linear encoders 96 y) corresponding tothe one head unit 60, and acquires 19Z position information (rotationquantity information) of the other head unit 60, on the basis of theoutput of, e.g., two X linear encoders 96 x (or, e.g., two Y linearencoders 96 y) corresponding to the other head unit 60. Main controller90 controls the position of head unit 60 in the Y-axis direction usingbelt driving device 68, on the basis of the position information of eachof the pair of head units 60 within the XY plane.

Now, as shown in FIG. 4A, at encoder base 54, scales 56, e.g., twoscales, are placed at a predetermined spacing in the Y-axis direction inareas at the +Y side and −Y side of projection optical system 16, as isdescribed above. Of the above two scales 56, e.g., placed at apredetermined spacing in the Y-axis direction, Y slide table 62 isdriven in the Y-axis direction between a position where head unit 60(all of the pair of X heads 64 x and the pair of Y heads 64 y (refer toFIG. 4C for each head)) faces scale 56 at the +Y side and a positionwhere head unit 60 faces scale 56 at the −Y side.

Similarly to the above mask encoder system 48, also in substrate encodersystem 50, the spacing between each head of the pair of X heads 64 x andeach head of the pair of Y head 64 y that one head unit 60 has is setwider than the spacing between the adjacent scales 56, as shown in FIG.4C. This allows at least one head of the pair of X heads 64 x toconstantly face X scale 57 x and at least one head of the pair of Yheads 64 y to constantly face Y scale 57 y, in substrate encoder system50. Substrate encoder system 50, therefore, is able to acquire positioninformation of Y slide table 62 (head unit 60) without interrupting themeasurement values.

Also, as shown in FIG. 7, two places (two points) separate from eachother in the X-axis direction on X scale 53 are irradiated withmeasurement beams from the pair of X heads 66 x, and two places (twopoints) separate from each other in the X-axis direction on Y scale 53 yare irradiated with measurement beams from the pair of Y heads 66 y.Substrate encoder system 50 supplies information on displacementquantity of substrate holder 34 (not shown in FIG. 7, refer to FIG. 2)to main controller 90 (refer to FIG. 8), by receiving beams from scalescorresponding to the above X heads 66 x and Y heads 66 y (not shown inFIG. 7, refer to FIG. 2). That is, in substrate encoder system 50, forexample, four X heads 66 x and X scales 53 x (different depending on theX position of substrate holder 34) facing X heads 66 x structure, forexample, four X linear encoders 94 x (not shown in FIG. 7, refer to FIG.8) for acquiring positional information of substrate P in the X-axisdirection, and, for example, four Y heads 66 y and Y scales 53 y(different depending on the X position of substrate holder 34) facing Yheads 66 y structure, for example, four Y linear encoders 94 y (notshown in FIG. 7, refer to FIG. 8) for acquiring position information ofsubstrate P in the Y-axis direction.

Main controller 90 acquires position information of substrate holder 34(refer to FIG. 2) in the X-axis direction and the Y-axis direction at aresolution of, for example, 10 nm or less, on the basis of the outputof, e.g., the four X linear encoders 94 x and the four Y linear encoders94 y, and the output of, e.g., the four X linear encoders 96 x, and thefour Y linear encoders 96 y (that is, the position information of eachof the pair of head units 60 in the XY plane), as shown in FIG. 8. Maincontroller 90 also acquires θZ position information (rotation quantityinformation) of substrate holder 34, on the basis of at least twooutputs of, e.g., four X linear encoders 94 x (or, e.g., four Y linearencoders 94 y). Main controller 90 controls the position of substrateholder 34 within the XY plane using substrate driving system 93, on thebasis of position information of substrate holder 34 within the XY planeacquired from the measurement values of the above substrate encodersystem 50.

Substrate holder 34, as described above, also has scales 52, e.g., five,which are placed at a predetermined spacing in the X-axis direction ineach of the areas at the +Y side and the −Y side of substrate P, as isshown in FIG. 4A. Also, of the above, e.g. five scales 52, placed in theX-axis direction at a predetermined spacing, substrate holder 34 isdriven in the X-axis direction between a position where head unit 60(all of the pair of X heads 66 x and the pair of Y heads 66 y (eachrefer to FIG. 4B)) faces scale 52 located outermost to the +X side, anda position where head unit 60 faces scale 52 located outermost to the −Xside.

Similarly to the above mask encoder system 48, the spacing between eachhead of the pair of X heads 66 x and each head of the pair of Y heads 66y that one head unit 60 has is set wider than the spacing between theadjacent scales 52, as shown in FIG. 4B. This allows at least one headof the pair of X heads 66 x to constantly face X scale 53 x and at leastone head of the pair of Y heads 66 y to constantly face Y scale 53 y, insubstrate encoder system 50. Substrate encoder system 50, therefore, isable to acquire position information of substrate holder 34 (refer toFIG. 4A) without interrupting the measurement values.

Referring back to FIG. 6, a dust-proof cover 55 consists of a memberextending in the Y-axis direction which has a XZ section formed in aU-shape, and the second section 54 b of encoder base 54 and Y slidetable 62 are inserted, via a predetermined clearance, in between a pairof opposing surfaces. At the lower surface of dust-proof cover 55,openings are formed through which X heads 66 x and Y heads 66 y pass.This suppresses adhesion of dust generated from parts such as Y linearguide device 63 and belt 68 c on scales 52. Also, a pair of dust-proofplates 55 a (not shown in FIG. 5) is fixed to the lower surface ofencoder base 54. Scales 56 are placed between the pair of dust-proofplates 55 a, which suppress adhesion of dust generated from parts suchas Y linear guide device 63 on scales 56.

FIG. 8 is a block diagram showing an input/output relation of maincontroller 90, which mainly structures a control system of liquidcrystal exposure apparatus 10 (refer to FIG. 1) and has overall controlover each section. Main controller 90, which includes a work station (ora microcomputer) or the like, has overall control over each section ofliquid crystal exposure apparatus 10.

In liquid crystal exposure apparatus 10 (refer to FIG. 1) having thestructure described above, under the control of main controller 90(refer to FIG. 8), a mask loader not shown performs loading of mask Monto mask stage apparatus 14, and a substrate loader not shown performsloading of substrate P onto substrate stage apparatus 20 (substrateholder 34). Main controller 90 then executes alignment measurement usingan alignment detection system not shown, and then, when the alignmentmeasurement has been completed, sequentially performs an exposureoperation of a step-and-scan method on a plurality of shot areas set onsubstrate P.

Next, an example of an operation of mask stage apparatus 14 andsubstrate stage apparatus 20 at the time of exposure operation will bedescribed, using FIGS. 9A to 16B. Note that, in the description below,although the case of setting four shot areas on one substrate P (thecase of setting four pieces) will be described, the number and placementof the shot areas set on one substrate P can be appropriately changed.

FIG. 9A shows mask stage apparatus 14 which has completed alignmentoperation, and FIG. 9B shows substrate stage apparatus 20 (members otherthan substrate holder 34 are not shown. The same applies to thedescription below) which has completed alignment operation. Exposureprocessing, as an example, is performed from a first shot area S₁ whichis set at the −Y side and also the +X side of substrate P, as shown inFIG. 9B. In mask stage apparatus 14, positioning of mask M is performedon the basis of the output of mask encoder system 48 (refer to FIG. 8),so that the edge at the +X side of mask M is positioned slightly to the−X side than the illumination area (in the state shown in FIG. 9A,however, illumination light IL is not irradiated yet on mask M) ofillumination light IL irradiated from illumination system 12 (refer toFIG. 1 for each section), as shown in FIG. 9A. To be more specific, forexample, the edge at the +X side of mask M is placed to the −X side withrespect to the illumination area, only by an entrance length necessaryto perform scanning exposure at a predetermined speed (that is,acceleration distance necessary to reach the predetermined speed), andat the position, scales 46 are arranged so that the position of mask Mcan be measured with mask encoder system 48. Also, in substrate stageapparatus 20, positioning of substrate P is performed on the basis ofthe output of substrate encoder system 50 (refer to FIG. 8), so that theedge at the +X side of the first shot area S₁ is positioned slightly tothe −X side than the exposure area (in the state shown in FIG. 9B,however, illumination light IL is not irradiated yet on substrate P) onwhich illumination light IL (refer to FIG. 1) from projection opticalsystem 16 is irradiated, as shown in FIG. 9B. To be more specific, forexample, the edge at the +X side of the first shot area S₁ of substrateP is placed to the −X side with respect to the exposure area, only by anentrance length necessary to perform scanning exposure at apredetermined speed (that is, acceleration distance necessary to reachthe predetermined speed), and at the position, scales 52 are arranged sothat the position of substrate P can be measured with substrate encodersystem 50. Note that, also when scanning exposure of the shot areas hasbeen completed and mask M and substrate P are decelerated, scales 46 and52 are arranged similarly so that mask encoder system 48 and substrateencoder system 50 can measure the position of mask M and substrate P,respectively, until mask M and substrate P have finished moving furtherby a deceleration distance necessary for deceleration to a predeterminedspeed from the speed at the time of scanning exposure. Alternatively,the position of mask M and substrate P may each be measured bymeasurement systems different from mask encoder system. 48 and substrateencoder system 50, during at least one of the operations of accelerationand deceleration.

Next, mask holder 40 is driven in the +X direction (acceleration,constant speed drive, and deceleration) as shown in FIG. 10A, andsynchronously with mask holder 40, substrate holder 34 is driven in the+X direction (acceleration, constant speed drive, and deceleration) asshown in FIG. 10B. When mask holder 40 is driven, main controller 90(refer to FIG. 8) performs position control of mask M on the basis ofthe output of mask encoder system 48 (refer to FIG. 8) as well asperform position control of substrate P on the basis of the output ofsubstrate encoder system 50 (refer to FIG. 8). When substrate holder 34is driven in the X-axis direction, the pair of head units 60 is to be ina stationary state. While mask holder 40 and substrate holder 34 aredriven at a constant speed in the X-axis direction, illumination lightIL (refer to FIG. 1 for each part) that has passed through mask M andprojection optical system 16 is irradiated on substrate P, and by thisoperation, the mask pattern that mask M has is transferred onto shotarea S₁.

When transfer of the mask pattern to the first shot area on substrate Pis completed, in substrate stage apparatus 20, substrate holder 34 isdriven (Y stepped) on the basis of the output of substrate encodersystem 50 (refer to FIG. 8) in the −Y direction by a predetermineddistance (a distance almost half of the dimension in the width directionof substrate P), for exposure operation of a second shot area S₂ set atthe +Y side of the first shot area S₁, as shown in FIG. 11B. In theabove Y step operation of substrate holder 34, mask holder 40 isstationary in a state where the edge of mask M at the −X side ispositioned slightly to the +X side than the illumination area (in thestate shown in FIG. 11A, however, mask M is not illuminated), as shownin FIG. 11A.

In the above Y step operation of substrate holder 34, as shown in FIG.11B, at substrate stage apparatus 20, the pair of head units 60 isdriven in the Y-axis direction synchronously with substrate holder 34.That is, main controller 90 (refer to FIG. 8) drives the pair of headunits 60 in the Y-axis direction via the corresponding belt drivingdevice 68 (refer to FIG. 8), on the basis of the output of Y linearencoders 96 y (refer to FIG. 8) of substrate encoder system 50 (refer toFIG. 8), while driving substrate holder 34 in the Y-axis direction to atarget position via substrate driving system 93 (refer to FIG. 8), onthe basis of the output of Y linear encoders 94 y. On this operation,main controller 90 drives the pair of head units 60 synchronously withsubstrate holder 34 (so that the pair of head units 60 follows substrateholder 34). Accordingly, each measurement beam irradiated from X heads66 x and Y heads 66 y (refer to FIG. 7 for each head) does not move awayfrom X scales 53 x and Y scales 53 y (refer to FIG. 7 for each scale),regardless of the Y position of substrate holder 34 (including whensubstrate holder 34 is moving). In other words, the pair of head units60 should move synchronously with substrate holder 34 in the Y-axisdirection, at a degree in which each of the measurement beams irradiatedfrom X heads 66 x and Y heads 66 y while substrate holder 34 is moved inthe Y-axis direction (during the Y step operation) do not move away fromX scales 53 x and Y scales 53 y, that is, at a degree in whichmeasurement by the measurement beams from X heads 66 x and Y heads 66 yis not interrupted (measurement can be continued).

When the Y step operation of substrate holder 34 is completed, as shownin FIG. 12A, mask holder 40 is driven in the −X direction on the basisof the output of mask encoder system 48 (refer to FIG. 8), andsynchronously with mask holder 40, as shown in FIG. 12B, substrateholder 34 is driven in the −X direction on the basis of the output ofsubstrate encoder system 50 (refer to FIG. 8). This allows the maskpattern to be transferred onto the second shot area S₂. The pair of headunits 60 is to be in a stationary state also on this operation.

When the exposure operation on the second shot area S₂ is completed, inmask stage apparatus 14, positioning of mask M is performed on the basisof the output of mask encoder system 48 (refer to FIG. 8), so that maskholder 40 is driven in the +X direction and the edge at the −X side ofmask M is positioned slightly to the +X side than the illumination area,as shown in FIG. 13A. Also, in substrate stage apparatus 20, positioningof substrate P is performed on the basis of the output of substrateencoder system 50 (refer to FIG. 8), so that substrate holder 34 isdriven in the +X direction and the edge at the −X side of a third shotarea S₃ is positioned slightly to the +X side than the exposure area,for exposure operation of the third shot area S₃ set at the −X side ofthe second shot area S₂ as shown in FIG. 13B. At the time of movingoperations shown in FIGS. 13A and 13B of mask holder 40 and substrateholder 34, illumination light IL is not irradiated with respect to maskM (refer to FIG. 13A) and substrate P (refer to FIG. 13B) fromillumination system 12 (refer to FIG. 1). That is, the moving operationsshown in FIGS. 13A and 13B of mask holder 40 and substrate holder 34 aresimply positioning operations (X step operations) of mask M andsubstrate P.

When the X step operations of mask M and substrate P are completed, inmask stage apparatus 14, as shown in FIG. 14A, mask holder 40 is drivenin the −X direction on the basis of the output of mask encoder system 48(refer to FIG. 48). And, synchronously with mask holder 40, as shown inFIG. 14B, substrate holder 34 is driven in the −X direction on the basisof the output of substrate encoder system 50 (refer to FIG. 8). Thisallows the mask pattern to be transferred onto the third shot area S₃.The pair of head units 60 is to be in a stationary state also on thisoperation.

When the exposure operation to the third shot area S₃ is completed, insubstrate stage apparatus 20, substrate holder 34 is driven (Y stepdrive) in the +Y direction by a predetermined distance for exposureoperation of a fourth shot area S₄ set at the −Y side of the third shotarea S₃, as shown in FIG. 15B. On this operation, like the time of the Ystep operation of substrate holder 34 shown in FIG. 11B, mask holder 40is to be in a stationary state (refer to FIG. 15A). The pair of headunits 60 is also driven in the +Y direction synchronously with substrateholder 34 (so as to follow substrate holder 34).

When the Y step operation of substrate holder 34 is completed, maskholder 40 is driven in the +X direction on the basis of the output ofmask encoder system 48 (refer to FIG. 8) as shown in FIG. 16A. And,synchronously with mask holder 40, substrate holder 34 is driven in the+X direction on the basis of the output of substrate encoder system 50(refer to FIG. 8) as shown in FIG. 16B. This allows the mask pattern tobe transferred onto the fourth shot area S₄. The pair of head units 60is to be in a stationary state also on this operation.

As described so far, with liquid crystal exposure apparatus 10 accordingto the present embodiment, because mask encoder system 48 for acquiringthe position information of mask M within the XY plane and substrateencoder system 50 for acquiring the position information of substrate Pwithin the XY plane (refer to FIG. 1 for each system) each have shortoptical path lengths of the measurement beams irradiated on thecorresponding scales, the influence of air fluctuation can be reducedwhen compared to, e.g., the conventional interferometer system. Thepositioning accuracy of mask M and substrate P, therefore, improves.Also, since the influence of air fluctuation is small, partialair-conditioning unit which is indispensable when using a conventionalinterferometer system can be omitted, which allows cost reduction.

Furthermore, in the case of using the interferometer system, large andheavy bar mirrors had to be equipped in mask stage apparatus 14 andsubstrate stage apparatus 20; however, with mask encoder system 48 andsubstrate encoder system 50 according to the present embodiment, theabove bar mirrors will not be necessary. This allows each of the systemsincluding mask holder 40 and the substrate holder 34 to be more compactand light as well as to have their weight balance improved, whichimproves position controllability of mask M and substrate P. Also, lessplaces need to be adjusted when compared to the case of using theinterferometer system, which allows cost reduction of mask stageapparatus 14 and substrate stage apparatus 14, and furthermore improvesmaintainability. Adjustment at the time of assembly also becomes easy(or unnecessary).

Also, in substrate encoder system 50 according to the presentembodiment, since the system employs the structure of measuring the Yposition information of substrate P by synchronously driving the pair ofhead units 60 (making the heads follow) in the Y-axis direction withsubstrate P, there is no need to place a scale extending in the Y-axisdirection at the substrate stage apparatus 20 side (or no need toarrange a plurality of heads in the Y-axis direction at the apparatusmain section 18 side). This simplifies the structure of the substratePosition measurement system, which allows cost reduction.

Also, in mask encoder system 48 according to the present embodiment,since the system employs the structure of acquiring the positioninformation of mask holder 40 in the XY plane while appropriatelyswitching the output of the pair of adjacent encoder heads (X head 49 x,Y head 49 y) according to the X position of mask holder 40, the positioninformation of mask holder 40 can be acquired without interruption, evenif a plurality of scales 46 are arranged at a predetermined spacing(spaced apart from one another) in the X-axis direction. Accordingly,there is no need to prepare a scale having a length equal to the movingstrokes of mask holder 40 (a length around three times of scale 46 ofthe present embodiment) in the system, which allows cost reduction, andmakes it suitable especially for liquid crystal exposure apparatus 10that uses a large mask M as in the present embodiment. Also similarly,in substrate encoder system 50 according to the present embodiment,since a plurality of scales 52 are placed in the X-axis direction and aplurality of scales 56 are placed in the Y-axis direction each at apredetermined spacing, scales having a length equal to the movingstrokes of substrate P do not have to be prepared, which makes itsuitable for application in liquid crystal exposure apparatus 10 whichuses a large substrate P.

Second Embodiment

Next, a second embodiment will be described, referring to FIG. 17. Sincethe structure of the second embodiment is the same as the above firstembodiment, except for the structure of a part of a mask encoder system148, only the difference will be described below, and components havingthe same structure and function as the above first embodiment will havethe same reference signs as the above first embodiment, and thedescriptions thereabout will be omitted.

As shown in FIG. 17, in mask encoder system 148 of the secondembodiment, a plurality of sensors 70 is fixed to unit base 45 of headunit 144. Main controller 90 (not shown in FIG. 17, refer to FIG. 8)detects marks not shown formed on scales 56 fixed to upper mount section18 a of apparatus main section 18 (or grid lines formed on scales 56)using the plurality of sensors 70, via through holes 72 which penetrateencoder base 43 and upper mount section 18 a, so as to acquireinformation on displacement quantity of Y heads 49 y and X heads 49 x ina direction parallel to the XY plane with respect to scales 56 (namely,apparatus main section 18). Main controller 90 performs position controlof mask holder 40, while correcting the measurement values (output of Yhead 49 y and output of X head 49 x) of mask encoder system 148, usingthe above information on displacement quantity (output of sensor 70).The type of sensor of sensor 70 is not limited in particular, and animage sensor similar to, for example, an aerial image measurement sensorcan be used.

According to the second embodiment, scales 56 serving as a reference forposition control of substrate holder 34, also function as a referencefor position control of mask holder 40. That is, mask encoder system 148and substrate encoder system 50 can be a single system (closed system),therefore, compared to the case when other members (e.g., projectionoptical system 16 (refer to FIG. 1)) serve as the reference for positioncontrol of mask holder 40, the system is free from the influence of thechange of posture of other members. Accordingly, this improves thepositioning accuracy of mask M and substrate P.

Third Embodiment

Next, a third embodiment will be described, referring to FIG. 18. Sincethe structure of the third embodiment is the same as the above firstembodiment, except for the structure of a part of a substrate encodersystem 150, only the difference will be described below, and componentshaving the same structure and function as the above first embodimentwill have the same reference signs as the above first embodiment, andthe descriptions thereabout will be omitted.

As shown in FIG. 18, in head units 160 that substrate encoder system 150of the third embodiment has, X heads 66 x and Y heads 66 y are eachattached to Y slide table 62 movable with fine strokes in the Z-axisdirection via Z actuators 76. The type of Z actuator 76 is not limitedin particular, and for example, parts such as a cam device, apiezoelectric element, a linear motor can be used. In substrate encodersystem 150, a Z sensor which is not shown constantly measures thedistance between each of the X heads 66 x, Y heads 66 y and the surfaceof scales 52 that substrate stage apparatus 20 has.

It is known that in the linear encoder system using an encoder head of adiffraction interference method as in the present embodiment, errorsoccur in the output of the encoder head due to a change in Z position ofthe scale surface (in the case of the present embodiment, X heads 66 xand Y heads 66 y each have sensitivity in the Z-axis direction,according to the Z position of substrate holder 34) (refer to, forexample, U.S. Patent Application Publication No. 2008/0094592).Therefore, main controller 90 (not shown in FIG. 18, refer to FIG. 8)finely drives each of a plurality of X heads 66 x and Y heads 66 yappropriately in the Z-axis direction, on the basis of the output of theabove Z sensor, so as to suppress the above errors that occur due to thechange in Z position of the scale. Accordingly, this improves thepositioning accuracy of substrate P. As the Z sensor, for example, a Zsensor of an optical pick-up method used in devices such as a CD drivemay be used, or the position information in the Z-axis direction may beacquired along with the position information of substrate holder 34 inthe X-axis direction (or Y-axis direction) with one encoder head, byusing, for example, X heads 66 x (or Y heads 66 y) and a two-dimensionalencoder as is disclosed in U.S. Pat. No. 7,561,280.

Note that, the structures of the first to third embodiments described sofar can be appropriately changed. For example, in the above mask encodersystem 48 and substrate encoder system 50 of the first embodiment, thearrangement of the encoder heads and the scales may be reversed. Thatis, for example, X linear encoders 92 x and Y linear encoders 92 y foracquiring position information of mask holder 40 may have the structurein which the encoder heads are attached to mask holder 40 and the scalesare attached to encoder base 43. Also, X linear encoders 94 x and Ylinear encoders 94 y used for acquiring position information ofsubstrate holder 34 may have the structure in which the encoder headsare attached to substrate holder 34 and the scales are attached to Yslide table 62. In this case, it is favorable for the encoder headsattached to substrate holder 34 to have the structure, for example, of aplurality of encoder heads placed along the X-axis direction that canperform switching operation mutually. Similarly, X linear encoders 96 xand Y linear encoders 96 y for acquiring position information of Y slidetable 62 may have the structure in which the scales are attached to Yslide table 62 and the encoder heads attached to encoder base 54(apparatus main section 18). In this case, it is favorable for theencoder heads attached to encoder base 54 to have the structure, forexample, of a plurality of encoder heads placed along the Y-axisdirection that can perform switching operation mutually. In the case theencoder heads are fixed to substrate holder 34 and encoder base 54, thescales fixed to Y slide table 62 may be shared.

Also in substrate encoder system 50, while the case has been describedwhere a plurality of scales 52 extending in the X-axis direction arefixed to the substrate stage apparatus 20 side and a plurality of scales56 extending in the Y-axis direction are fixed to the apparatus mainsection 18 side (encoder base 54) side, the arrangement is not limited,and a plurality of scales extending in the Y-axis direction may be fixedto the substrate stage apparatus 20 side and a plurality of scalesextending in the X-axis direction may be fixed to the apparatus mainsection 18 side. In this case, head units 60 are driven in the X-axisdirection synchronously with substrate holder 34 at the time of exposureoperation of substrate P.

Also, while the case has been described where in mask encoder system 48,for example, three scales 46 are placed apart in the X-axis direction,and in substrate encoder system 50, for example, two scales 52 areplaced apart in the Y-axis direction, and for example, five scales 56are placed apart in the X-axis direction, the number of scales is notlimited to this. For example, the number of scales can be appropriatelychanged according to the size of mask M, substrate P, or the movingstrokes. Also, the plurality of scales do not necessarily have to beplaced spaced apart, and for example, a longer single scale may be used(in the case of the above embodiments, for example, a scale having alength around three times as that of scale 46, a scale having a lengtharound two times as that of scale 52, and a scale having a length aroundfive times as that of scale 56).

Also, while the case has been described where X scales and Y scales areformed independently on the surface of each of the scales 46, 52, and56, the scales are not limited to this, and for example, XYtwo-dimensional scales may also be used. In this case, the encoder headscan also use the XY two-dimensional heads. Also, while the case has beendescribed where the encoder system of a diffraction interference methodis used, the system is not limited to this, and other encoders thatemploys a so-called pick-up method, or a magnetic encoder can be used,and for example, a so-called scan encoder like the one disclosed in, forexample, U.S. Pat. No. 6,639,686 can also be used. Also, positioninformation of Y slide table 62 may be acquired by a measurement systemother than the encoder system (for example, an optical interferometersystem).

Also, substrate stage apparatus 20 only has to drive at least substrateP along a horizontal plane in long strokes, and in some cases, does nothave to perform fine positioning in directions of six degrees offreedom. The substrate encoder system according to the above first tothird embodiments can suitably applied, even to such two-dimensionalstage apparatus.

Also, the illumination light may be ultraviolet light such as an ArFexcimer laser light (wavelength 193 nm), KrF excimer laser light(wavelength 248 nm), or vacuum-ultraviolet light such as an F₂ laserlight (wavelength 157 nm). Also, as the illumination light, for example,a harmonic wave may be used, which is a single-wavelength laser beamingthe infrared or visual region oscillated from a DFB semiconductor laseror a fiber laser amplified by an erbium-doped (or erbium-and-ytterbiumdoped) fiber amplifier, and then whose wavelength is converted into theultraviolet light using a nonlinear crystal. Also, solid-state lasers(wavelength: 355 nm, 266 nm) may also be used.

Also, while the case has been described where projection optical system16 is a projection optical system of a multiple lens method equippedwith a plurality of optical systems, the number of projection opticalsystems is not limited to this, and one or more will be fine. Also, theprojection optical system is not limited to the projection opticalsystem of a multiple lens method, and may also be an Offner typeprojection optical system which uses a large mirror. Also, as projectionoptical system 16, a magnifying system or a reduction system may also beused.

Also, the exposure apparatus to which the embodiments are applied is notlimited to the exposure apparatus for liquid crystals which transfersthe liquid crystal display device pattern onto a square-shaped glassplate, and may also be widely applied, for example, to an exposureapparatus for manufacturing organic EL (Electro-Luminescence) panels, anexposure apparatus for manufacturing semiconductors, or to an exposureapparatus for manufacturing thin film magnetic heads, micromachines, andDNA chips. Also, the above embodiments can be applied not only to anexposure apparatus for manufacturing microdevices such assemiconductors, but also to an exposure apparatus that transfers acircuit pattern onto a glass substrate or a silicon wafer to manufacturea reticle or a mask used in an optical exposure apparatus, an EUVexposure apparatus, an X-ray exposure apparatus, and an electron-beamexposure apparatus.

Also, the object subject to exposure is not limited to a glass plate,and may also be other objects, such as, for example, a wafer, a ceramicsubstrate, a film member, or a mask blanks. Also, in the case theexposure object is a substrate for a flat panel display, the thicknessof the substrate is not limited in particular, and includes, forexample, a film-like substrate (a sheet-like member having flexibility).It is to be noted that the exposure apparatus of the present embodimentis especially effective in the case when the exposure object is asubstrate whose length of aside or diagonal length is 500 mm or more.

Electronic devices such as liquid crystal display devices (orsemiconductor devices) are manufactured through the steps such as; astep for performing function/performance design of a device, a step formaking a mask (or a reticle) on the basis of this design step, a stepfor making a glass substrate (or a wafer), a lithography step fortransferring a pattern of a mask (reticle) onto the glass substrate bythe exposure apparatus and the exposure method described in each of theabove embodiments, a development step for developing the glass substratewhich has been exposed, an etching step for removing by etching anexposed member of an area other than the area where the resist remains,a resist removing step for removing the resist that is no longernecessary since etching has been completed, a device assembly step, andan inspection step. In this case, in the lithography step, because thedevice pattern is formed on the glass substrate by carrying out theexposure method previously described using the exposure apparatus of theabove embodiments, this allows a highly integrated device to bemanufactured with good productivity.

It is to be noted that all publications, international publications,U.S. patent application Publications, and U.S. patents quoted in theabove embodiments related to the exposure apparatus and the like, intheir entirety, are incorporated herein by reference.

INDUSTRIAL APPLICABILITY

As described above, the movable body apparatus and the movable bodydrive method of the present invention are suitable for driving a movablebody along a predetermined two-dimensional plane. Also, the exposureapparatus of the present invention is suitable for forming apredetermined pattern on an object. Also, the manufacturing method offlat panel displays of the present invention is suitable for producingflat panel displays. Also, the device manufacturing method of thepresent invention is suitable for producing microdevices.

REFERENCE SIGNS LIST

-   10 . . . liquid crystal exposure apparatus,-   14 . . . mask stage apparatus,-   20 . . . substrate stage apparatus,-   34 . . . substrate holder,-   40 . . . mask holder,-   44 . . . head unit,-   46 . . . scale,-   48 . . . mask encoder system,-   50 . . . substrate encoder system,-   52 . . . scale,-   56 . . . scale,-   60 . . . head unit,-   90 . . . main controller,-   M . . . mask,-   P . . . substrate.

The invention claimed is:
 1. An exposure apparatus that performsscanning exposure of an object by relatively driving the object withrespect to an optical system, the apparatus comprising: a first movablebody that holds the object and is movable in a first direction and asecond direction intersecting each other; a reference member serving asa reference for movement of the first movable body in the firstdirection and the second direction; a second movable body disposedbetween the first movable body and the reference member, and movable inthe second direction; a first measurement system that acquires positioninformation of the first movable body in the first direction withrespect to the reference member, with a first head disposed at one ofthe first movable body and the second movable body and a first scaledisposed at the other of the first movable body and the second movablebody that can measure a movement range of the first movable body in thefirst direction at the time of the scanning exposure; and a secondmeasurement system that acquires position information of the firstmovable body in the second direction with respect to the referencemember, with a second head disposed at one of the second movable bodyand the reference member and a second scale disposed at the other of thesecond movable body and the reference member that can measure a movementrange of the first movable body in the second direction at the time ofthe scanning exposure.
 2. The exposure apparatus according to claim 1,further comprising: a control system that controls a position of thefirst movable body with respect to the reference member, wherein thefirst measurement system acquires the position information by the firsthead measuring the first scale having a measurement component in thesecond direction, the second measurement system acquires the positioninformation by the second head measuring the second scale having ameasurement component in the first direction, and the control systemcontrols the position of the first movable body with respect to thereference member, on the basis of the position information acquired bythe first measurement system and the second measurement system.
 3. Theexposure apparatus according to claim 1, wherein the object is asubstrate used in a flat panel display.
 4. The exposure apparatusaccording to claim 3, wherein the substrate has at least one of a sidelength and a diagonal length that is 500 mm and over.
 5. A manufacturingmethod of a flat panel display, comprising: exposing the object usingthe exposure apparatus according to claim 1; and developing the objectwhich has been exposed.
 6. A device manufacturing method, comprising:exposing the object using the exposure apparatus according to claim 1;and developing the object which has been exposed.
 7. An exposure methodin which scanning exposure of an object is performed by relativelyscanning the object with respect to an optical system, the methodcomprising: acquiring position information of a first movable body,which holds the object and is movable in a first direction and a seconddirection intersecting each other, in the first direction with respectto a reference member, using a first measurement system having a firsthead disposed at one of a second movable body and the first movable bodyand a first scale disposed at the other of the second movable body andthe first movable body that can measure a movement range of the firstmovable body in the first direction at the time of the scanningexposure, the second movable body being disposed between the firstmovable body and the reference member, and being movable in the seconddirection; and acquiring position information of the first movable bodyin the second direction with respect to the reference member, using asecond measurement system, having a second head disposed at one of thesecond movable body and the reference member and a second scale disposedat the other of the second movable body and the reference member, thatcan measure a movement range of the first movable body in the seconddirection at the time of scanning exposure.
 8. The exposure methodaccording to claim 7, further comprising: controlling a position of thefirst movable body with respect to the reference member, wherein thefirst measurement system acquires the position information by the firsthead measuring the first scale having a measurement component in thesecond direction, the second measurement system acquires the positioninformation by the second head measuring the second scale having ameasurement component in the first direction, and the position of thefirst movable body with respect to the reference member is controlled,on the basis of position information acquired by the first measurementsystem and the second measurement system.